html{
    font-size: 10px;
}

body{
    font-family: -apple-system, BlinkMacSystemFont, "Helvetica Neue","PingFang SC","Microsoft YaHei", "Source Han Sans SC","NoTo Sans CJK" ,"WenQuanyi Micro Hei",san-serif
    font-size:16px
    background-image:url(https://ss3.bdstatic.com/70cFv8Sh_Q1YnxGkpoWK1HF6hhy/it/u=2022383369,3230585108&fm=26&gp=0.jpg)
    background-repect:no-repect;
}

h1{
    font-weight: bolder;
    font-size: 1cm;
    text-align: center;
    letter-spacing: 2px;

}

section{
    font-size: 20px;
}
p{
    font-size: 1.5rem;
    line-height: 1.5;
    text-indent: 2em;
}
h2{

}
.three3D{color: cyan;
    text-shadow: darkgreen;
    
}
.demo3{
    text-shadow: 005px #fff; 
}

#text-prop div{
    width: 20vw;
    height: 20vh;
    background-color: coral;
}

#bg-section{
    background-color: darkorange;
    background-image: url(https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1585120870447&di=9fdb2375d6689a04208ade613e097bd4&imgtype=0&src=http%3A%2F%2F5b0988e595225.cdn.sohucs.com%2Fimages%2F20180713%2Fe1a60d2881c241a5bfec74f9fdfc515c.jpeg);
}

.box-demo{
    border: 2px white double;
    height: 100px;
    width: 100px;
    text-align: center;
    line-height: 100px;
    margin-top: 1rem;
    border-radius: 5px;
    box-shadow: darkslategrey;
}
footer{
    border-top: 1px solid  crimson;
    margin-top: 5rem ;
}
footer p{
    text-align: center;
    text-indent: 0%;
    font-size: 12px;
}

footer span{
    margin: 0 2rem;
}